1. Field of the Invention
The present invention relates to a signal transfer apparatus, and more particularly to a light-signal transmitting apparatus, a light-signal receiving apparatus, a light-signal transfer apparatus and a light-signal transfer method with which a signal reproduced by audio equipment of video equipment is emitted to a space as a light signal, such as an infrared ray to transfer the signal to the other audio equipment or the video equipment.
2. Related Art of the Invention
Audio equipment, such as a digital audio disk reproducing apparatus, is sometimes provided with a light-signal transfer apparatus using, for example, an infrared ray to permit a user to easily operate the apparatus. The light-signal transfer apparatus, which is provided for the audio equipment, has a light emitting diode arranged to be operated in response to an audio signal to emit, to a space, an infrared ray having an intensity corresponding to the level of the audio signal. The emitted infrared ray is transferred to a receiving apparatus. The receiving apparatus having a light receiving device arranged to receive the infrared ray to demodulate the audio signal so as to reproduce the audio signal through a loud speaker unit, earphone or the like.
However, the light-signal transfer apparatus using the infrared ray must be structured as shown in FIG. 1 in such a manner that a light signal S1 is directly emitted from a light emitting portion 1 to a light receiving portion 2. That is, the transfer passage for the infrared ray arranged to be transferred through a space must be formed into a linear shape using a direct light beam. It leads to a fact that the transfer passage is intercepted if an obstacle 3, such as a human being, exists between the light emitting portion 1 and the light receiving portion 2, as shown in FIG. 2. Therefore, the light signal S1 is blocked attributable to the interception of the transfer passage, thus causing a problem to arise in that the audio signal cannot be transferred.
In view of the foregoing, an object of the present invention is to provide a light-signal transmitting apparatus, a light-signal receiving apparatus, a light-signal transfer apparatus and a light-signal transfer method each of which is capable of continuously reproducing signals even if the transfer passage is temporarily intercepted.